If you think Yoga is all about twisting our body in different ways, it's much different than that. In simple words, Yoga consists of taking care of our minds, body and breath. This means that Yoga is all about meditation, pranayamas (breathing styles) and Yoga asana (postures). So when the mind, breath and body are in sync, it's called Yoga.
Yoga is also known as physical, mental and spiritual practices to achieve peace. Hindu spiritual monks like Swami Vivekananda introduced Yoga to the West